Installation of the device is very easy. After charging for about 3hours, you can install on either your PDA or any BT enabled laptop. Remember, the pair key is four zeros (0000), in case the application asks for it. All tests here were carried out using an ASUS A6JA laptop. We logged all produced data for a pre-selected route with VisualGPSX and later analyzed it with GPSLog.

In order to record the TTFF measurements ("Time to First Fix" which is the time it takes for a GPS to determine its current position), we used the GPSInfo "Cold Start" function. All tests ran simultaneously, under the same environmental conditions while driving around in an Audi, model A4 2004.

The retail package doesn't offer any kind of testing software. However, if you visit the Polstar Technologies website, you can download two software packages, one for PDAs and one for PC platforms.

- Tests Day One

On the first day we tested the device, it was daylight with a clear sky, and a temperature of 28° C.

Globalsat BT-338

Polstar i-GeoPro PBT-648

Time to First Fix (TTFF)

Secs

38 sec

46 sec

Fix

Invalid

2.1

2.9

2D

14.7

3.4

3D

83.2

93.7

Satellites

Average (in view)

8.16

9.75

Average (in use)

4.47

4.57

Average Signal Level (in dB)

Maximum per Satellite

31.83

33.00

Average per Satellite

26.19

26.68

The PBT-648 showed good performance, very similar to the BT-338. In fact, in most cases, it performed better than the BT-338.

- Tests Day Two

On the second day of testing, we had partly-cloudy daylight conditions, with 30° C.

Globalsat BT-338

Polstar i-GeoPlus PBT-648

Time to First Fix (TTFF)

Secs

39 sec

40 sec

Fix

Invalid

0

0

2D

0

0

3D

100

100

Satellites

Average (in view)

8.00

9.00

Average (in use)

6.71

6.59

Average Signal Level (in dB)

Maximum per Satellite

38.00

38.10

Average per Satellite

32.85

31.99

It is not surprising to see such close results from the two devices since they are both powered by the SiRF III chipset. There are some minor differences in the max and average levels, but not enough to be concerned with.

- Tests Day Three ( Indoor Sensitivity)

We placed both receivers inside a house, close to a large window and monitored their performance. The Polstar PBT-648 had a 3D fix with 6 in view and 4 in use satellites, whereas the Globalsat Globalsat BT-338 had a 3D fix with 7 in view and 5 in use satellites.

- Overall impressions

The Polstar i-Geo Plus PBT-648, is powered by the SiRF III chipset as we have already mentioned. The device showed typical SiRF III performance, good reception levels, good sensitivity and quick TTFF times. The Globalsat BT-338 seemed to be slightly better tuned, especially for indoor use. Most users however, won't even notice the differences.